1. Field of the Invention
The present invention relates to a driving control system for a vehicle, which enables a vehicle to pass through a corner or the like on a road at an appropriate vehicle speed by utilizing a so-called navigation system including a map information output means for outputting a map, and a vehicle position detecting means for detecting a vehicle position on the map.
2. Description of Relevant Art
There is a conventionally known driving information display apparatus utilizing a navigation system, as described, for example, in Japanese Patent Application Laid-open No. 89298/85.
Such driving information display apparatus is capable of not only displaying a map and a vehicle position on a display surface, but also detecting a corner through which the vehicle cannot pass at a current vehicle speed over a given section in a traveling direction of the vehicle on the basis of the travel distance and the radius of curvature of the corner on a road on the map; calculating an appropriate vehicle speed at which the vehicle can properly pass through such corner, and displaying such information to attract a driver's attention.
In the above known technique, the accuracy of the appropriate vehicle speed is largely dependent upon the accuracy of calculation of the radius of curvature of a corner on a road, i.e., the accuracy of the map provided by the navigation system. However, the accuracy of the map provided by the known navigation system is insufficient for correctly calculating the radius of curvature of the corner. Moreover, the above known technique suffers from a problem that the calculation of the radius of curvature of the corner is complicated and, hence, a calculating device of a large capacity is required.